Safety-razor



Dec. 31, 1935. C, A GRA-|101- 2,026,229

SAFETY RAZOR Filed DBG. 15, 1935 Fica. 15.

Snnentor Cheste-rA.Grati.o12.

Gttorneg Patented Dec. 31, 1935 1 UNITED STATES.

PATENT oFF-ICE My invention relates to safety-razors of the type in which a thin double-edged blade is clamped between a guardpiece and cap constituting forming members by means of winch the blade is attached to a handle and strained to alter its normal mechanical properties and adjust the disposition of the cutting edges with reference to the said guard-piece and handle.

The principal object of my invention is the provision of a safety-razor having improved properties relatingto facility of use in shaving, efficacy of operation, and endurance of the shaving edges. f

A second object is the provision of certain adjustments inherent in the device facilitating 1- cleaning. A third object is the lprovision of unique and ecient clamping means facilitating assembly and separation of the several parts for washing,

l drying, and sterilizing.

Other objects and advantages of my invention will be apparent in the following discourse wherein the significance of the reference characters in the accompanying drawing, details of construction of a typical safety-razor of my invention and the particular advantages thereof areexplained.

Figure 1 represents a view in perspective of the entire razor as assembled and adjusted for so use.

Figure 2 represents a view in perspective of the entire razor as adjusted for washing, drying and storage.

Figure 3 represents a view of the concave side of the razor cap.

Figure 4 represents a'view of a 'section on the line 4-4 of Figure 3.

Figure 5 represents a view of a blade typical of the kind adapted for use in therazor of my 40 invention.

Figure 6 represents a view of the convex side of the guard-piece. i

Figure 7 represents a view of the edgeof the guardpiece in perspective;

Figure 8 represents a view of the end of thel guard-piece in perspective.

Figure 9` represents a view of the handle of the razor.

Figure 10 is a diagram illustrative of the form of the convex surface ofthe guard-piece.

Figure 11 is a diagram illustrative of certain relationships between the blade and the cap.

Figure 12 represents a view of a typical trans- 55 verse section through the cap, blade, and guardpiece particularly showing the relationship therebetween.

Figure 13 is a'diagram illustrative of certain effects accruing in the blade by virtue of use in the razor of my invention. 5.

My invention contemplates for the accomplishment of the objects set forth:

An unusuallyrigid convex cutting edge disposed through its length at a variety of angles to the axis of the handle with respect to any 10 aspect thereof so that a selection of angles between the skin and the blade and between the .cutting edge and the direction of motion of the razor may be available upon the shifting of the razor laterally, and, conversely, so that by 15 shifting the razor laterally to effect an oblique stroke the cutting angle of the successively conp. tacting portions of the .convex edge may be maintainedata constant value when the motion of the razor is pivotalabout the wrist of 20 the user as is natural; Y A manner of adjustment of the razor without disconnecting the pieces providing for the separation of the cap, guard, and blade to permit the passage therebetween of water, sterilizing liquids 25 or gases, and air;

vMeans providing for the rapid assembly of the razor without unnecessary movements; and

Means providing for the straining of the cutting edges in tensile stress to enhance the rigid'- 3o `ity thereof.

The razor is composed of a cap 3 one surface p of which conforms to an oblique segment of a prolate spheroid to form the concave surface against which the blade 5 is clamped by a con- 35 Y vex surface complementary -thereto formed on the guard-piece S. This convex surface of the guard-piece 6 is illustrated in the diagram Figure 10 where the convex surface of the guardpiece is shown as coincident with the surface of 40 theprolate spheroid Il. l

The curvatures of the concave surface of the cap 3, the convex surface of the guard-piece 6, and the two faces of the blade 5, will be somewhat different-to compensate for the thickness ai of the blade 5 andthe ilexure of the cap and guard when the same are clamped together with a concentrated'pressure. The cap and guard, however, are so formed as to provide for the disposition of the cutting edges of the blade in co- 5o incidence with the surface of-a prolate spheroid of the approximate form illustrated in Figure 10.

The. cap 3 is formed with a plate I5 perpendicular to a middle tanget of the cap, andvapproximately in the center thereof. The upper longitudinal axis asillustrated in the diagram Figure 11l at 20 which depicts the approximate aspect of the relationship as developed in a cylindrical projection, the magnitude of this inclination, however, being exaggerated.

a curved surfaces 22 and 23 are milledfrom end 'I'he convex surface of the guard 8 conforms to the prolate-spheroidal surface to the outer j margins of the slots I9 and 2|. Between these outer-slotmargins and the edges two inclined to end. The profiles of these edge sections are shown particularly in Figure l2 at 24 and 25,

and are also illustrated in the end view of theA guard in Figure 8.

i The handle 9, illustrated in Figure 9, is formed with a yoke 26 fitted with a pin 2I situated at a distance from lthe ends of the yoke-halves greater than half the width of the yoke.

To assemble the razor,. the cap 3 is placed in the palm ofthe hand with the plate I5 projecting upwardly, the blade 5 is next placed over the plate I5 and the guard placed over the blade. The plate I5 extends through the slot I8 of the blade and theslot 20 of the guard'and projects above the concave surface of the guard 6 when these pieces are thus loosely assembled.

The handle 9 is now grasped in the other hand and the edges of the yoke-halves are brought to bear upon the concave surface of the guard 6 with the handle in that relative position shown in Figure 2. Pressure upon the guard in this m'anner will cause the flexure of the blade and the further projection of the plate I5. The pin 21 of the handle may now be engaged with the hook I6 of the plate I5 by a. slight longitudinal movement of the handle. When this is done the razor will appear as illustrated in Figure 2.

In this adjustment it is to be noticed that the guard, blade and cap are separated by appreciable distances. This relationship of these parts provides for easy washing of the razor which is securely held by the coaction ofthe strains in the blade and the hook I6 of the plate l5.

Tov adjust the razor for shaving the handle is raised to the perpendicular position as illustrated in Figure l when the cap 3 and guard 6 will be firmly pressed together by the toggle action inherent in this movement, and the blade will be formed as described.

In addition to those advantages and special properties of a. razor of the general form of the oblique cylindrical segment as described in my applicationfor Letters Patent of the United States for Safety-razors, filed January l'l, 1933, Serial No. 652,133, the present invention provides these further unique advantages and properties:

My present invention provides for the critical equality and uniformity of relationship of the cutting edges of the blade with the edges of the guard. It will be apparent from a study of the 16 form of the blade which is characterized by a v aussage longitudinal slot paralleilwith parallel cutting edges, and a study of the disposition of the plate 'I5 upon the cap 3 and the disposition of the slot 20 of the guard 6 slightly inclined from the true center lines of these parts as shown at 20' in 5 Figure 11, that the cutting edges of the blade will be brought into parallelism with the edges vof the guard 6 when the assembly is. clamped scribed, compensations for the foreshortening of the blade due to varying degrees of curvature of the blade, must be provided in the relative dispositions ofthe plate I5 and the slot 20 with reference to the edges of the cap and guard respectively.

Figure 11 villustrates this provision. The

.brokenlines represent the form of the blade-and Athe solid lines represent the form of the guard .with reference thereto, the slot being coincident with the blade slot 20 shown in broken 25 lines. If the upper left hand and the lower right hand corners of the guard with blade superimposed thereupon as illustrated in this gure are bent backwardly the outlines of the blade and the guard will at some point of exure a0 become parallel, or nearly so. Hence in the present invention I have disposed the plate I5 and slot 20 of the cap and guard respectively at slight inclination from the true center lines of these parts.

The inclined surfaces 22 and 23 of the guard 6 provide for a definite and fixed clearance below the entire length of the cutting edges of the blade without interruption and as well provide for the disposition `of the cutting edges well 'down into the channels formed by this milling so that if a straight-edge be laid across the edges of the cap and guard the cutting edge at any point willappear below the straight-edge.

Reference to my previous invention before referred to will disclose that reliance was had solely upon bending stresses in the blade to dispose the cutting edges thereof at the proper position. This is in contrast to the present invention wherein another force is provided for which ellects the disposition of the cutting edges as just described. In the present invention I have provided that the cutting edges of the blade shall also be subject to a tensile stress to improve the rigidity of the edges as well as the positioning thereof with reference to the guard edges.

Tensioning of cutting edges is a practice acknowledged by saw-makers to improve the rigidity of the armed edges and applies with equal 30 propriety andeffect in razors. The means I have chosen to produce this effect reside in the prolate spheroidal forms described to which a normally fiat blade is strained. The effects of such strainingr are illustrated in the diagram c5 Figure 13.

Each half of the blade assumes a position tending toward those illustrated in this figure.

- The slot becomes wider in the middle and the obvious from a study of the drawing. u

Having described my invention what I claim 1. A safety-razor in which a normally fiat exible blade having parallel cutting edges and a central longitudinal slot parallel therewith is clamped between a can and a guard having blade-contacting surfaces conforming to an oblique segment of the surface of a prolate spheroid, wherein blade-holding means engaging said longitudinal slot in said blade incline toward corners of'sald cap and guard characterized by curvatures ofleast radii.

y2. A safety-razor having a cap and guard with blade clamping surfaces conforming to a segment of the surface of a prolate spheroid, a hook attachedv to said cap and extending through said guard, and a handle attachable tov said hook to secure the whole together.

3. A safety-razor having a cap and guard with blade-clamping surfaces conforming to an oblique segment of the surface of a prolate spheroid, a hook attached to said cap and extending through said guard, and a handle attachablexo said hook to secure the whole together. f

4. A safety-ramr having a cap and, guard with blade clamping surfaces conforming substa'ntially to oblique segments of the surfaces of prolate spheroids, a normally ilat flexible blade clamped between said cap and guard, a hook s attached to said cap and extending through said guard and said blade. and a handle attachable to said hook to secure the whole together.

5. A safety-razor comprising, Aa normally fiat flexible blade and a cap and a guard between 10 which said blade is clamped, said guard and said cap having blade-contacting surfaces conforming substantially to complementary oblique sur'- facesegments of prolate spheroids.

6. A safety-razor comprising. a normally flat 1s flexible blade having parallel cutting edges and a longitudinal slot therebetween, a cap and a guard between which said blade is clamped ntted with means to engage said slot and align said blade, said cap and said guardhaving blade- 20 contacting surfaces conforming Substantially to complementary oblique surface-segments of prolate spheroids.

CHESTER A. GRATIOT. 

